Refrigerator

ABSTRACT

A refrigerator includes: a cabinet defining a first storage space, a door including a drawer part that defines a second storage space inside the first storage space and a door part that is mounted on a front surface of the drawer part to open and close the second storage space, a door gasket sealing a gap between the cabinet and the door, a draw-out motor configured to provide a driving force for a drawing out operation of the door, and a controller configured to control the draw-out motor. The controller is configured to count a number of rotations of the draw-out motor for a set period of time based on the draw-out motor being started for opening of the door according to received input, and stop and re-operate, based on a draw-out distance of the door being shorter than a set distance, the draw-out motor.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority to and the benefit of KoreanPatent Application No. 10-2020-0010656, filed on Jan. 29, 2020, thedisclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a refrigerator.

BACKGROUND

A refrigerator is a home appliance that allows low-temperature storageof food in an internal storage space that is shielded by a door. To thisend, the refrigerator is configured to store the stored food in anoptimal state by cooling the interior of the storage space using coldair generated through heat exchange with a refrigerant circulatingthrough a refrigeration cycle.

Recently, a refrigerator is gradually becoming larger andmultifunctional in accordance with changes in dietary life and a trendof high-end products. Accordingly, refrigerators with various structuresand convenience devices that enable users' convenience and efficient useof the internal space thereof are being introduced.

The storage space of the refrigerator may be opened and closed by adoor. In addition, the refrigerators may be classified into varioustypes of refrigerators according to the arrangement of storage spacesand the structure of the door opening and closing the storage space.

The refrigerator door may be classified into a rotation type door thatopens and closes a storage space by rotation, and a drawer-type doorthat is drawn in and out in a drawer type.

In addition, the drawer-type door is often disposed in a lower area ofthe refrigerator or a plurality of drawer doors is disposed on upper andlower sides. Accordingly, in order for the user to store food in thedrawer-type door, it is essential for the user to hold and draw in thedrawer-type door in until the drawer-type door is completely closed.

In addition, there is a problem in that the user needs to bend theuser's body when performing operation for opening and closing thedrawer-type door disposed at the lowest side.

In order to solve such a problem, a conventional refrigerator having astructure in which a drive device such as a separate motor and a buttonor switch which a user operates are provided and a drawer-type door isautomatically drawn in and out.

In addition, the conventional refrigerator is further provided with alifting mechanism for lifting and lowering a bin provided in arefrigerating chamber.

SUMMARY

The present disclosure is directed to a refrigerator capable ofimproving convenience of a drawer door.

According to one aspect of the subject matter described in thisapplication, a refrigerator includes a cabinet defining a first storagespace, a door including (i) a drawer part that defines a second storagespace inside the first storage space and (ii) a door part that ismounted on a front surface of the drawer part to open and close thesecond storage space, a door gasket made of an elastically deformablematerial and provided along a periphery of the door part to seal, basedon the door being closed, a gap between the cabinet and the door, adraw-out motor configured to provide a driving force for a drawing outoperation of the door, a detector configured to detect an open/closestate of the door, a manipulation part configured to receive user inputto control an operation of the draw-out motor, and a controllerconfigured to control the draw-out motor. The controller can beconfigured to count a number of rotations of the draw-out motor for aset period of time based on the draw-out motor being started for openingof the door according to the received input of the manipulation part,and stop and re-operate, based on a draw-out distance of the door beingshorter than a set distance, the draw-out motor.

Implementations according to this aspect can include one or more of thefollowing features. For example, the controller can be configured tore-operate the draw-out motor in a direction in which the door is drawnout after the draw-out motor is stopped.

In some implementations, the controller can be configured to re-operatethe draw-out motor to (i) rotate in a reverse direction in which thedoor is drawn in and (ii) rotate, based on the draw-out motor beingstopped, in a forward direction in which the door is drawn out. In someimplementations, the controller can be configured to re-operate thedraw-out motor repeatedly a plurality of times.

In some examples, the draw-out distance can be calculated based on afrequency generator (FG) detection signal of the draw-out motor. In someimplementations, the detector can be configured to detect a completionof the drawing out operation of the door.

In some implementations, the set distance can be set to a distanceextendable while the door gasket is in contact with the cabinet. In someimplementations, the door gasket includes a gasket fixing portion fixedto a rear surface of the door part, a close-contact portion contacting afront surface of the cabinet and including a magnet, and a connectionportion that is configured to connect the gasket fixing portion to theclose-contact portion and that extends based on the open/close state ofthe door. The front surface of the cabinet can be made of a steelmaterial or can include a magnetic material.

In some examples, the set distance can be set to a maximum distancethrough which the door gasket is able to extend while the close-contactportion is attached to the cabinet. In some examples, the set distancecan be within a range of 20 mm to 30 mm.

In some implementations, the set period of time can be a period of timeuntil the door gasket is completely separated from the cabinet in astate in which the door that was opened is closed. In someimplementations, the controller can be configured to output, based onthe door not being opened after the draw-out motor is re-operated, adoor opening failure signal.

In some examples, the refrigerator can further include a display or aspeaker, and the controller can be configured to output, based on thedoor not being opened within the set period of time, a door openingfailure through the display or the speaker. In some examples, thecontroller can be configured to reversely rotate, based on the door notbeing opened within the set period of time, the draw-out motor to closethe door.

In some implementations, the draw-out motor can be provided on a bottomof the cabinet, and the drawer part can include a draw-out rack that iscoupled to a pinion rotated by the draw-out motor on a bottom thereof.In some implementations, an output of the draw-out motor can be smallerthan a value for overcoming a maximum negative pressure based on thedoor being opened. In some implementations, the second storage spacethat is opened and closed by the door can be a freezing space.

In some examples, the refrigerator can further include a drive deviceprovided inside the door part, and a lifting device provided inside thedrawer part and configured to be connected to the drive device based onthe door part and the drawer part being coupled to lift the drawer part.In some examples, the refrigerator can further include a lift detectiondevice configured to detect a completion of a lifting and loweringoperation of the lifting device, and the draw-out motor can beconfigured to be driven based on the lifting device being lowered.

In some examples, the door can be drawn out to a distance where a frontspace inside the drawer part in which the lifting device is disposed iscompletely exposed, and a rear end of the drawer part is positionedinside the first storage space.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a front view of an exemplaryrefrigerator.

FIG. 2 is a diagram illustrating a cross-sectional view schematicallyshowing a lifted state of a lower drawer door of an exemplaryrefrigerator.

FIG. 3 is a diagram illustrating a partial cross-sectional view showinga lower structure of the exemplary refrigerator.

FIG. 4 is a diagram illustrating a perspective view of the lower drawerdoor as viewed from the rear.

FIG. 5 is a diagram illustrating an exploded perspective view of thelower drawer door as viewed from the front in which a drawer part and adoor part are separated from each other.

FIG. 6 is a diagram illustrating an exploded perspective view of thedrawer door in a state which a lifting device is separated from thedrawer door.

FIG. 7 is a diagram illustrating a rear perspective view of the doorpart from which a door cover is removed.

FIG. 8 is a diagram illustrating a perspective view of a drive deviceand the lifting device connected to each other.

FIG. 9 is a diagram illustrating a front perspective view of the drivedevice.

FIG. 10 is a diagram illustrating a rear perspective view of an innerstructure of the drive device.

FIG. 11 is a diagram illustrating a partial enlarged view of a structurein which a driving force is transmitted to a screw of the drive device.

FIG. 12 is a diagram illustrating a perspective view of a liftingdevice.

FIG. 13 is a diagram illustrating a view showing a state in which anupper frame of the lifting device is lifted.

FIG. 14 is a diagram illustrating a partial enlarged view showing astate in which a lifting device is coupled to a lever.

FIG. 15 is a block diagram schematically showing a controller andcomponents connected to the controller.

FIG. 16 is a flow chart showing the drawing-in/out and lifting/loweringoperation of the drawer door.

FIG. 17 is a diagram illustrating a perspective view of the lower drawerdoor in a closed state.

FIG. 18 is a diagram illustrating a perspective view of the lower drawerdoor which is fully opened.

FIG. 19 is a diagram illustrating a cross-sectional view of the drawerdoor when the basket of the lower drawer door has been completelylowered.

FIG. 20 is a diagram illustrating a perspective view showing the drivedevice and the lifting device in the state of FIG. 19.

FIG. 21 is a diagram illustrating a cross-sectional view of the drawerdoor in a state in which the basket of the lower drawer door is fullylifted.

FIG. 22 is a diagram illustrating a perspective view showing the drivedevice and the lifting device in the state of FIG. 21.

FIG. 23 is a diagram illustrating a cross-sectional view showing a statein which the drawer door cannot be opened.

FIG. 24 is an exemplary graph showing a change in pressure duringoperation for opening the drawer door.

FIG. 25 is a flowchart sequentially illustrating an operation of drawingout the drawer door.

DETAILED DESCRIPTION

FIG. 1 is a diagram illustrating a front view of an exemplaryrefrigerator. FIG. 2 is a diagram illustrating a cross-sectional viewschematically showing a lifted state of a lower drawer door of anexemplary refrigerator. Further, FIG. 3 is a diagram illustrating apartial cross-sectional view showing a lower structure of the exemplaryrefrigerator.

Referring to FIGS. 1-3, a refrigerator 1 can have an appearance by acabinet 10 defining a storage space and a door 2 shielding a frontsurface of the cabinet 10 which defines an opening.

The storage space inside the cabinet 10 can be divided into a pluralityof spaces. For example, an upper space 11 of the cabinet 10 can beprovided for a refrigerating chamber, and a lower space 12 of thecabinet 10 can be provided for a freezing chamber. It is noted that theupper space and the lower space can be provided for separate spacesmaintained at different temperatures rather than a refrigerating spaceor a freezing space, and can be referred to as an upper space and alower space.

The door 2 can include a rotating door 20 that opens and closes theupper space by rotation, and a drawer door 30 that opens and closes thelower space by drawing in/out in a drawer type. The lower space can bedivided into an upper portion and a lower portion, and the drawer door30 can include an upper drawer door 30 a and a lower drawer door 30 b.

In some implementations, the external surfaces of the rotating door 20and the drawer door 30 are provided with a metal material to define anappearance exposed to the front.

The refrigerator 1 is presented with the rotating door 20 and the drawerdoor 30, but the present disclosure is not limited thereto, and can beapplicable to all types of refrigerators provided with a door which isdrawn in/out in a drawer type. In some implementations, the rotatingdoor 20 can be provided at an upper portion to be referred to as anupper door, and the drawer door 30 can be provided at a lower portion tobe referred to as a lower door.

A display 211 can be provided on a portion of front surface of therotating door 20, and the display 211 can include a structure of aliquid crystal display (LCD) or an 88 segment structure.

In some implementations, when the external surface of the door 2 isprovided with a metal material, the display 211 can be provided suchthat a plurality of fine holes are perforated to display information bytransmitted light.

In some implementations, a manipulation part 212 capable of operatingautomatic rotation or drawing-in/out of the upper door 2 or the lowerdoor 2 can be provided in a portion of the rotary door 20.

The manipulation part 22 can be provided integrally with the display 211and can be operated by a touch method or a button method. Themanipulation part 212 can input/operate a command for the overalloperation of the refrigerator 1, and can operate the drawing-in/out ofthe drawer door 30 and the lifting/lowering of the drawer door 30.

A manipulation part 301 can also be provided on the drawer door 30. Themanipulation part 301 can be provided in a portion of the lower drawerdoor 30 b positioned at the lowest portion of the drawer door 30, andthe manipulation part 301 can be configured in a touch or button manner.It should be noted that the manipulation part 301 can include a sensorthat detects a user's proximity or movement, or can be configured toreceive an operation by the user's motion or speech.

In some implementations, a manipulation device 302 can be provided at alower portion of the lower drawer door 30 b and configured to output avirtual switch by projecting an image onto the floor and enable anoperation to be input in a manner that the user approaches acorresponding area.

In order to store or receive food inside the lower drawer door 30 b, thelower drawer door 30 b can be drawn out forward, and then the basket 36located inside the lower drawer door 30 b can be operated so as to belifted.

The lower drawer door 30 b can be referred to as a drawer door or adoor. Further, the lower drawer door 30 b is not limited to the numberand shape of drawer doors.

The basket 36 inside the door 30 can be lifted and lowered by a drivedevice 40 and a lifting device 80 provided in the lower drawer door 30b.

In some implementations, the basket 36 can be accommodated in the door30 in a manner that the basket 36 is lifted and lowered. The basket 36can have a predetermined height. Since the basket 36 is seated on thelifting device 80, the height of the basket 36 can be added to theheight of the lifting device 80 to be exposed to the outside when thelifting device 80 is lifted. Therefore, when the lifting device 80 islifted, a user can be located at a point where it is very easy for theuser to approach the basket 36 or lift the basket 36.

In some implementations, a draw-out motor 14 configured draw in/out thedoor 30 can be provided at the bottom of the inside of the cabinet 10.The draw-out motor 14 can be provided at the bottom of the storage space12, and a pinion gear 141 rotated by the draw-out motor 14 can befurther provided. The pinion gear 141 can be directly or indirectlyconnected by the draw-out motor 14 and can be configured to be coupledto a draw-out rack 34 provided at the bottom of the door 30. A pair ofdraw-out racks 34 can be provided on the left and right sides, and thus,a pair of pinion gears 141 coupled to the draw-out racks 34 can also beprovided at a corresponding position. Accordingly, the door 30 can beautomatically drawn in and out by the drive of the draw-out motor 14,and the storage space 12 can be opened and closed. In someimplementations, the draw-out motor 14 and the pinion gear 141 can befurther provided on a barrier 121 for the drawing-in/out of the upperdrawer door 30 a.

Referring to FIG. 3, the cabinet 10 can be composed of an outer case 101and an inner case 102 and an insulating material can be filled betweenthe outer case 101 and the inner case 102 to insulate the storage space12. In some implementations, the door 30 can also be insulated by theouter plate 311 of the door 30, the door liner 314, and an insulatingmaterial 312 provided therebetween.

The storage space 12 can be divided into an upper portion and a lowerportion by the barrier 121. The barrier 121 can connect the left andright sides of the inside of the storage space 12 at the front end ofthe storage space 12, and be in close contact with the door gaskets 317provided on the doors 30 at the upper and lower sides. For example, onestorage space 12 can be divided into a plurality of spaces for usage.

The door gasket 317 can allow the storage space 12 to be airtight whenthe door 30 is closed, be formed along the periphery of the rear surfaceof the door part 31, and contact the front end of the cabinet 10 and thefront end of the barrier 121.

In some implementations, the door gasket 317 can be provided with anelastically deformable material such as rubber or silicone, and can becompressed when the door 30 is closed to be completely in close contactwith the front surface of the cabinet 10 and the front surface of thebarrier 121. In some implementations, the door gasket 317 can have astructure that limits leakage between the door 30 and the storage space12.

For example, the door gasket 317 can include a gasket fixing portion 317a fixed to a door liner 314, a close-contact portion 317 d that is inclose contact with the front surface of the cabinet 10 or the barrier121, and gasket connection portions 317 b and 317 c connecting thegasket fixing portion 317 a and the close-contact portion 317 d.

The gasket fixing portion 317 a can have a structure capable of beingpress-fit into a gasket mounting groove 314 a formed along the peripheryof the door liner 314 defining the rear surface of the door part 31.Therefore, in some implementations, after the gasket fixing portion 317a is pressed and fitted into the gasket mounting groove 314 a, the doorgasket 317 may not be easily separated.

In some implementations, the close-contact portion 317 d can be formedin a planar shape that is in contact with the front surface of thecabinet 10 or the barrier 121, and a magnet 317 e can be providedtherein. Due to the magnetic force of the magnet 317 e, the door gasket317 can be in close contact with the front surface of the cabinet 10 orthe barrier 121. For example, the front surface of the cabinet 10 or thebarrier 121 can be provided with a metal material, and a metal or amagnet can be provided inside the cabinet 10 or the barrier 121.Therefore, the close-contact portion 317 d can be kept in close contactwith the front surface of the cabinet 10 or the barrier 121 due to themagnetic force of the magnet 317 e to limit the door gasket 317 frombeing very easily separated from the front surface of the cabinet 10 orthe barrier 121. For example, when the door 30 is completely closed, aset compression distance L1 can be maintained between the rear surfaceof the door part 31 and the front end of the cabinet 10.

In some implementations, the gasket fixing portion 317 a and theclose-contact portion 317 d can be connected by the gasket connectionportions 317 b and 317 c. The gasket connection portions 317 b and 317 ccan include a first connection portion 317 c and a second connectionportion 317 b respectively extending from an upper end and a lower endof the close-contact portion 317 d, and the first connection portion 317c and the second connection portion 317 b can have different lengths.For example, the second connection portion 317 b can be longer than thefirst connection portion 317 c.

For example, when the door 30 is opened and the door gasket 317 isseparated from the front surface of the cabinet 10 or the barrier 121,the first connection portion 317 c having a short length is firstseparated, and the second connection portion 317 b is separated in astate where the close-contact portion 317 d is inclined. In a state inwhich the close-contact portion 317 d is in close contact with the frontsurface of the cabinet 10 or the barrier 121 by the magnetic force, aforce enabling the door gasket 317 to be separated from the frontsurface of the cabinet 10 or the barrier 121 can be required at anappropriate level. For example, it is possible to limit too much forceto open the door 30 due to excessive adhesion. Further, the door gasket317 can be further extended by a predetermined length in an airtightstate due to its elasticity and the structure of the gasket connectionportions 317 b and 317 c when the door 30 is opened.

In some implementations, a grill pan 16 can be provided inside thestorage space 12. The grill pan 16 can define at least a part of therear wall of the storage space 12 and define a heat exchange space 131in which an evaporator 13 is accommodated. The evaporator 13 can beprovided at the rear of the grill pan 16. Cold air generated by theevaporator 13 can be supplied to the inside of the storage space througha discharge port provided in the grill pan 16, be recovered through asuction port, and be again subjected to heat exchange by the evaporator13. The storage space 12 can be then cooled to a set temperature bycirculation of the cold air.

FIG. 4 is a diagram illustrating a partial cross-sectional view showinga lower structure of the refrigerator 1. FIG. 5 is a diagramillustrating an exploded perspective view of the lower drawer door asviewed from the front in which the drawer part and the door part areseparated from each other. FIG. 6 is a diagram illustrating an explodedperspective view of the drawer door in a state which a lifting device isseparated from the drawer door.

Referring to FIGS. 4-6, the door 30 can include a door part 31 thatopens and closes the storage space, and a drawer part 32 that is coupledto the rear surface of the door part 31 and is drawn in and out with thedoor part 31.

The door part 31 can be exposed to the outside of the cabinet 10 todefine the appearance of the refrigerator 1, and the drawer part 32 canbe disposed inside the cabinet 10 to define a storage space. In someimplementations, the door part 31 and the drawer part 32 can be coupledto be withdrawn in and out in the front and rear directions.

The drawer part 32 can be positioned on the rear surface of the doorpart 31, and can define a space in which food for storage or the basket36 is accommodated. The drawer part 32 can define a storage space, whichis open upward and the inner and outer appearances of the drawer part 32can be formed by a plurality of metal plates. The plurality of platescan be provided outside as well as inside of the drawer part 32 so thatthe entire drawer part 32 can be formed of or stainless steel or have atexture such as stainless steel.

In a state in which the door 30 is drawn in, a machine room including acompressor and a condenser constituting a freezing cycle can be disposedbehind the door 30. Accordingly, the rear portion of the drawer part 32can have a shape in which an upper portion protrudes more than a lowerportion, and the rear surface of the drawer part 32 can include aninclined surface.

In some implementations, draw-out rails 33 can be provided at both sidesof the drawer part 32 to guide the drawing-in/out of the door 30. Thedoor 30 can be mounted so as to be drawn out and in the cabinet 10 bythe draw-out rails 33. The draw-out rail 33 can be configured in a railstructure that can extend in multiple stages.

A draw-out rack 34 can be provided on a lower surface of the drawer part32. The draw-out rack 34 can be disposed on both sides, and is connectedwith the drive of the draw-out motor 14 mounted on the cabinet 10 toenable automatic drawing-out/in of the door 30. For example, during theoperation of the manipulation part 212 or 301, the draw-out motor 14 isdriven so that the door 30 can be drawn out/in according to the movementof the draw-out rack 34. In some implementations, the door 30 can bestably drawn out and in by the draw-out rail 33.

In some implementations, the drawer part 32 may not be provided with thedraw-out rack 34, or the drawer part 32 may be configured such that theuser directly draws in/out the door 30 in a manner that the user pushesor pulls the door 30 while holding one side of the door part 31.

In some implementations, the inside of the drawer part 32 can be dividedinto a front space S1 and a rear space S2. In the front space S1, alifting device 80 that is configured to be lifted up and down, and abasket 36 that is configured to be seated on the lifting device 80 andlifted together with the lifting device 80 can be disposed.

In some implementations, when the door 30 is drawn out, the entiredrawer part 32 cannot be drawn out of the storage space due to limits inthe draw-out distance of the door 30, and at least the front space S1can be drawn out of the storage space, and all or a part of the rearspace S2 can be disposed inside the storage space of the cabinet 10.

The reason for the above-described structure is that the draw-outdistance of the door 30 can be limited by the draw-out rack 34 or thedraw-out rail 33. As the draw-out distance increases, the moment appliedto the door 30 increases in the state in which the door 30 is drawn out,making it difficult to maintain a stable state and causing deformationor damage of the draw-out rail 33 or the draw-out rack 34.

In the front space S1, the lifting device 80 and the basket 36 can beaccommodated. When the lifting device 80 is being lifted up and down,the food on the lifting device 80 and or the basket 36 can be lifted andlowered together. In some implementations, the lifting device 80 can beprovided under the basket 36, and when the basket 36 is mounted, thelifting device 80 can be covered by the basket 36, thus enabling anyconfiguration of the lifting device 80 from not being exposed to theoutside.

A separate drawer cover 37 can be provided in the rear space S2. Thefront space S1 and the rear space S2 can be separated by the drawercover 37. When the drawer cover 37 is mounted, the front and uppersurfaces of the rear space S2 can be shielded so that an unused space isnot exposed to the outside.

Due to mounting of the drawer cover 37, the rear space S2 is coveredwhen the door 30 is drawn out, and the front space S1 is only exposedwhen the door 30 has been drawn out, thereby providing a cleanerappearance. In some implementations, the remaining space except for thespace in which the lifting device 80 and the basket 36 are mounted canbe covered to limit a problem such as a food drop or a product jammingin a gap during lifting.

In some implementations, a door light 318 can be provided on the rearsurface of the door part 31. The door light 318 can brighten the insideof the drawer part 32, and can be positioned at an upper side withrespect to the drawer part 32.

In some implementations, the lifting device 80 is disposed inside thedrawer part 32, and the basket 36 can be seated on the upper surface ofthe lifting device 80. The basket 36 can be lifted from the drawer asneeded, and can be lifted together with the lifting device 80.

In some implementations, in order to utilize the entire space inside thedrawer part 32, the lifting device 80 inside the drawer part 32 can besimply detachably mounted, and the lifting device 80 and the drawercover 37 can be separated from the drawer part 32, thus utilizing theentire inner space of the drawer part 32.

In some implementations, the door part 31 and the drawer part 32constituting the door 30 can have a structure in which the door part 31and the drawer part 32 are separated from and coupled to each other.Assembly workability and serviceability can be improved through thedetachable structures of the door part 31 and the drawer part 32.

The rear surface of the door part 31 and the front surface of the drawerpart 32 can be coupled to each other, and when the door part 31 and thedrawer part 32 are coupled to each other, a driving force for liftingand lowering the lifting device 80 can be provided.

A drive device 40 for lifting the lifting device 80 can be disposed inthe door part 31, and the door part 31 and the drawer part 32 can beselectively connected.

For example, the drive device 40 provided in the door part 31 caninclude components operated by the input of a driving force andcomponents for transmitting the driving force to the lifting device 80.Accordingly, when the service of the drive device 40 is required, thedoor part 31 can be separated to take action, and only the door part 31can be replaced, so that a simple action can be taken.

The door part 31 and the drawer part 32 can be coupled by a pair of doorframes 316 provided on both sides. The door frame 316 can be configuredto be connected to the rear surface of the door part 31 and both sidesof the drawer part 32, respectively.

When the door part 31 and the drawer part 32 are coupled to each other,a drawer opening 35 through which a part of the lifting device 80 isexposed can be formed in the front surface of the drawer part 32 suchthat the drive device 40 and the lifting device 80 can be connected toeach other.

A scissor side connection portion 842 serving as a rotation axis of thelifting device 80 can be exposed to the inside of the drawer opening 35.For example, when the scissor side connection portion 842 is connectedto the drive device 40, the lifting device 80 can be in an operablestate. In some implementations, the drawer openings 35 can be formed atboth left and right side ends of the front surface of the drawer part32.

In some implementations, the lifting device 80 has a structure that canbe separated from the drawer part 32 according to the user's operation.For example, the scissor side connection portion 842 of the liftingdevice 80 and a lever side connection portion 422 of the drive device 40connected to each other are first separated, and the lifting device 80is then lifted from the drawer part 32.

The door part 31 is configured to open and close the storage space ofthe cabinet 10 and at the same time define the front appearance of therefrigerator 1.

The door part 31 can have an outer appearance defined by an outer case311 defining the front surface and a part of peripheral surfaces and adoor liner 314 defining a rear surface. Further, insulating material 312can be filled in the inside of the door part 31 between the outer case311 and the door liner 314.

FIG. 7 is a diagram illustrating a rear perspective view of the doorpart from which a door cover is removed. FIG. 8 is a diagramillustrating a perspective view of the drive device and the liftingdevice connected to each other.

The drive device 40 for operating the lifting device 80 can be providedinside the door part 31. In some implementations, drive device 40 isdisposed inside the door part 31, but can also be provided inside aspace defined by the door liner 314 instead of being buried in theinsulating material. Further, the door liner 314 can be formed in ashape corresponding to the shape of the drive device 40 and the doorlight 318 to provide a space in which the drive device 40 and the doorlight 318 are mounted.

In some implementations, the drive device 40 can be shielded by the doorcover 315 so as not to be exposed to the outside. Both sides of thelower end of the door cover 315 can be open, and the lever sideconnection portions 422 of a lever 42, which is a component of the drivedevice 40, can be exposed.

In some implementations, the lever-side connection portion 422 can belocated at a position facing the drawer opening 35. For example, whenthe door part 31 and the drawer part 32 are connected, the opening ofthe door cover 315 and the drawer opening 35 can communicate with eachother. Thus, the lever-side connection portion 422 and the scissor-sideconnection portion 842 of the lifting device 80 can be coupled throughthe door cover 315 and the drawer opening 35.

The door gasket 317 can be provided along the peripheries of the rearsurface of the door part 31, and when the door 30 is closed, the doorgasket 317 can contact at the front surface of the cabinet 10 and thebarrier 121 to make the storage space airtight.

The drive device 40 can be shielded by the door cover 315 and disposedinside the door part 31. The drive device 40 can be connected to thelifting device 80, and a driving force of the drive device 40 can betransmitted to the lifting device 80. For example, the drive device 40can simultaneously transmit a driving force to both the left and rightsides of the lifting device 80 so that the lifting device 80 does notincline or tilt to one side under any circumstances, and be lifted orlowered in a state in which the both sides are horizontal.

The drive device 40 can include a motor assembly 60, a pair of screwunits 50 disposed on both sides of the motor assembly 60, and a pair oflevers 42 respectively connected to the screw units 50. In someimplementations, the screw unit 50 can include a screw 52 and a screwholder 56 that is penetrated by the screw 52 and is lifted and loweredalong the screw unit 50.

In some implementations, the lever 42 can include a lever-sideconnection portion 422 formed at one end of a lever extension portion421, and the lever-side connection portion 422 can be rotatably fixed tothe rear surface of the door part 31. Further, a lever hole 423 throughwhich a holder fastening member is fastened can be formed at the otherend of the lever extension portion 421.

The lever hole 423 is formed in a long hole shape and can guide themovement of the holder fastening member 564, and simultaneously allowthe holder fastening member 564 to be fastened to the screw holder 56.Accordingly, the lever 42 can be rotated by the screw holder 56 which islifted and lowered when the screw 52 is rotated.

FIG. 9 is a diagram illustrating a front perspective view of the drivedevice. FIG. 10 is a diagram illustrating a rear perspective viewshowing an inner structure of the drive device. FIG. 11 is a diagramillustrating a partial enlarged view showing a structure in which adriving force is transmitted to a screw of the drive device.

Referring to FIGS. 9 to 11, a motor assembly 60 can be positioned in acenter portion in the left-right direction of the door part 31. In someimplementations, the screw units 50 and 50 a and the levers 42 on bothsides can be configured to be operated by the driving of the motorassembly 60 including a drive motor 64.

For example, the motor assembly 60 can adjust the magnitude of a forceto be decelerated and transmitted through a combination of a pluralityof gears.

In some implementations, the motor assembly 60 can have a structure inwhich the drive motor 64 and the gears are arranged vertically in orderto minimize a space that is depressed when mounted on the door part 31.For example, the motor assembly 60 can be formed to widen a width in aleft-right direction to minimize the thickness of the motor assembly 60and to minimize the thickness in a front-rear direction.

In some implementations, the drive motor 64 constituting the motorassembly 60 can protrude toward the drawer part 32 to minimize adepression depth of the door part 31, thus ensuring thermal insulationperformance.

The drive motor 64 can provide a driving force for the lifting of thelifting device 80 and can be configured to rotate forward and reversely.Accordingly, when a lifting signal of the lifting device 80 is input,the drive motor 64 is rotated forward or reversely, thereby providing adriving force for lifting the lifting device 80. In someimplementations, the drive motor 64 can be stopped when a load of thedrive motor 64 or a stop signal is input due to detection of a sensor.

The motor assembly 60 can include a motor case 61 in which the drivemotor 64 is installed, and a motor cover 62 coupled to the motor case 61to cover the drive motor 64.

A rotation shaft of the drive motor 64 can protrude from the motor case61 toward the opposite side of the motor cover 62. In someimplementations, the motor assembly 60 can further include a drivingforce transmission part for transmitting the driving force of the drivemotor 64. The driving force transmission part can be located on theopposite side of the drive motor 64 with respect to the motor case 61.

In some implementations, the driving force transmission part can beformed of a combination of a plurality of gears, and can be shielded bya cover member 66 mounted on the opposite side of the drive motor 64.

The driving force transmission part can include a drive gear 651connected to the shaft of the drive motor 64 passing through the motorcase 61. The driving force transmission part can further include a firsttransmission gear 652 meshing with the drive gear 651 on a lower side ofthe drive gear 651.

The first transmission gear 652 can be, for example, a multi-stage gear.For example, the first transmission gear 652 can include a first gear652 a meshing with the drive gear 651 and a second gear 652 b having adiameter smaller than that of the first gear 652 a. Each of the firstgear 652 a and the second gear 652 b can be a spur gear.

The driving force transmission part can further include a secondtransmission gear 653 meshing with the first transmission gear 652. Thesecond transmission gear 653 can mesh with the first transmission gear652 on the lower side of the first transmission gear 652. The secondtransmission gear 653 can include a first gear 653 a meshing with thesecond gear 652 b of the first transmission gear 652, and a second gear653 b having a diameter larger than that of the first gear 653 a.

Each of the first gear 653 a and the second gear 653 b of the secondtransmission gear 653 can be a spur gear. In some implementations, thesecond gear 653 b of the second transmission gear 653 can be locatedbelow the first gear 652 a of the first transmission gear 652.Accordingly, an increase in a width of the drive device 40 in thefront-rear direction can be limited by the first transmission gear 652and the second transmission gear 653.

The driving force transmission part can further include a thirdtransmission gear 654 meshing with the second transmission gear 653. Thethird transmission gear 654 can mesh with the second gear 653 b on thelower side of the second gear 653 b of the second transmission gear 653.The third transmission gear 654 can be a spur gear. A portion of thethird transmission gear 654 can be disposed so as to overlap the secondtransmission gear 653 in the front-rear direction.

A gear shaft for rotatably supporting the plurality of transmissiongears can be provided in the motor case 61.

The driving force transmission part can include a pair of crossing gears655 and 656 meshing with the third transmission gear 654. The pair ofcrossing gears 655 and 656 can be arranged to be spaced apart from eachother in the left-right direction and engage with the third transmissiongear 654 at a position where the rotation center thereof is lower thanthe rotation center of the third transmission gear 654.

The crossing gears 655 and 656 respectively include spur gear parts 655a and 656 a of a spur gear type and helical gear parts 655 b and 656 bof a helical gear type such that the crossing gears 655 and 656 engagewith the third transmission gear 654. It can include first helical gearunits 655 b and 656 b.

In addition, rotation center lines of the crossing gears 655 and 656spaced apart from each other to the left and the right may extendhorizontally to each other.

The driving force transmission part can further include a pair of secondhelical gear parts 657 and 657 a respectively meshing with the crossinggears 655 and 656.

The second helical gear parts 657 and 657 a can mesh with the firsthelical gear parts 655 b and 656 b. The rotation center lines of thesecond helical gear parts 657 and 657 a can be disposed to intersect therotation center lines of the crossing gears 655 and 656. Accordingly,the first helical gear parts 655 b and 656 b and the second helical gearparts 657 and 657 a can intersect with each other, and can be configuredto engage with each other to transmit rotation.

The rotation center lines of the crossing gears 655 and 656 can extendin the front-rear direction, and the rotation center lines of the secondhelical gear parts 657 and 657 a can extend in the vertical direction.Further, the rotation center lines of the second helical gear parts 657and 657 a disposed on both left and right sides can be inclined in adirection in which they are further far from each other toward the upperside.

As described above, the use of a pair of bevel helical gears has theadvantage that the driving force transmission direction can be easilyswitched and the structure for transmission of a driving force becomescompact. For example, even when a large force is transmitted for thelifting of the lifting device 80, a large noise is not caused.

The pair of screw units 50 and 50 a can be disposed on both left andright sides of the motor assembly 60.

The pair of screw units 50 and 50 a are disposed on both left and rightsides of the inside of the door part 31, and the pair of screw units 50and 50 a have the same structure and shape except their mountingpositions.

The driving force of the drive motor 64 can be transmitted from thelower portions of the screw units 50 and 50 a.

The screw units 50 and 50 a on both sides can be formed to besymmetrical with respect to the motor assembly 60. Accordingly, themotor assembly 60 can be disposed between the screw units 50 and 50 apositioned on both sides, and the screw units 50 and 50 a disposed onboth sides can be arranged such that a distance between the screw units50 and 50 a gets closer as it goes from the upper ends to the lowerends.

The screw units 50 and 50 a can include screws 52 and 52 a that arerotated by receiving a driving force from the drive motor 64. The screw52 or 52 a can extend in a vertical direction, and be inclined such thatthe upper end is directed to the outside and the lower end is directedto the inside.

The screws 52 and 52 a can be connected to the second helical gear parts657 and 657 a. For example, the screws 52 and 52 a can be rotatedtogether when the second helical gear parts 657 and 657 a are rotated.

For example, an insertion portion can be formed in the second helicalgear part 657 or 657 a, and an accommodation groove in which theinsertion portion is accommodated can be formed in the screw 52.

Accordingly, the screws 52 and 52 a can also be disposed to besymmetrical on the left and right sides with respect to the motorassembly 60, and can be disposed to be inclined on the same center lineas the center line of the second helical gear parts 657 and 657 a.Accordingly, the screws 52 and 52 a on the left and right sides can bearranged such that they are further spaced apart from each other as itgoes upward.

The screw units 50 and 50 a can further include screw holders 56 and 56a through which the screws 52 and 52 a are coupled.

The screw holders 56 and 56 a can be moved vertically along the screws52 and 52 a when the screws 52 and 52 a are rotated. In someimplementations, the levers 42 can be respectively coupled to the screwholders 56 and 56 a. When the screw holders 56 and 56 a are moved, thelevers 42 can be rotated.

For example, a holder through hole 561 is formed in the center of thescrew holder 56 or 56 a. The holder through hole 561 is formed to passthrough the screw holder 56 or 56 a, and the screw 52 or 52 a isinserted into and mounted to the holder through hole 561 by passingthrough the holder through hole 561. A thread coupled to the screw canbe formed in an inner surface of the holder through hole 561.Accordingly, when the screws 52 and 52 a are rotated, the screw holders56 and 56 a are movable along the screws 52 and 52 a.

In some implementations, guide holes 562 are formed on both left andright sides of the holder through hole 561. The guide hole 562 is aportion through which the guide bar 53 or 54 passes, and the screwholders 56 and 56 a can be moved along the guide bars 53 and 54.

The guide bars 53 and 54 can be formed in a round bar shape, and can beformed of a metal material to stably support the screw holders 56 and 56a.

A bearing is provided on the inner surface of the guide hole 562 tofacilitate the movement of the screw holder 56 or 56 a. Further, asleeve-shaped lubrication member through which the guide bar 53 or 54passes can be provided in the guide hole 562. The lubrication member canbe formed of an engineering plastic or a material that reduces friction,thus facilitating movement of the screw holders 56 and 56 a and limitingnoise from occurring. It should be noted that, if necessary, the screwholders 56 and 56 a themselves can be formed of an engineering plasticmaterial.

Since a pair of the guide bars 53 and 54 are configured to pass throughthe guide holes 562, the screw holders 56 and 56 a do not move to theleft and right, thus enabling stable lifting and lowering. For example,stable lifting is possible even in a situation where a heavy load isapplied to drive the lifting device 80, and noise does not also occur.

In some implementations, a magnet 563 can be provided in the screwholder 56 a. For example, a magnet mounting groove 563 a in which amagnet is press-fitted can be formed in the screw holder 56 a, and canhave a structure in which the magnet 563 can be inserted into the magnetmounting groove 563 a.

The magnet 563 is for detecting a position of the screw holder 56 a.When the screw holder 56 a is located at the lower end or upper end ofthe screw 52 or 52 a, a lift detection device 55 can detect the positionof the screw holder 56 a. For example, it is possible to determine thecompletion of the lifting and lowering of the lifting device accordingto whether the magnet 563 mounted in the screw holder 56 a is detected.

Further, the holder connector can be mounted on the opposite side of therear surface of the screw holder 56 a in which the magnet 563 isprovided, that is, the front surface of the screw holder.

The holder connector is for connecting the lever 42 and the screw holder56 or 56 a, and can be fixedly mounted to the screw holder 56 or 56 a.That is, the holder connector can be coupled to the screw holder 56 or56 a while passing through the lever 42. The lever 42 can include arectangular slot 426 such that the lever 42 does not interfere with theholder connector during the rotation of the lever 42.

Since the screw units 50 and 50 a are disposed on the left and rightsides, extension lines of the screws 52 and 52 a on the left and rightsides can cross each other outside of the drive device 40.

The lever 42 can connect the screw holder 56 or 56 a and the liftingdevice 80, and both ends can be coupled to the screw holder 56 or 56 aand the lifting device 80, respectively.

The screw units 50 and 50 a can further include housings 51accommodating the screws 52 and 52 a, respectively.

The housing 51 which defines an outer shape of the screw unit 50 or 50 acan define a space in which screw 52 or 52 a and the screw holder 56 or56 a are accommodated, and an open portion can be shielded by a covermember 66.

The housing 51 can be formed by bending a plate-shaped metal material orcan be formed of a plastic material.

The housing 51 can include a first accommodating portion 511accommodating the screw 52 or 52 a, and a second accommodating portion512 accommodating the second helical gear portion 657 or 657 a.

The first accommodating portion 511 and the second accommodating portion512 can be separated from each other by a partition wall 513. The secondaccommodating portion 512 is located below the first accommodatingportion 511.

A portion of the crossing gear 655 or 656 can be accommodated in thesecond accommodating portion 512. For example, the crossing gear 655 or656 can be connected to the second helical gear part 657 or 657 a insidethe second accommodating portion 512.

A lower portion of the screw 52 or 52 a passes through the partitionwall 513, and the second helical gear part 657 or 657 a is coupled tothe screw 52 or 52 a that has passed through the partition wall 513.

One or more guide bars 53 and 54 for guiding the lifting of the screwholder 56 or 56 a can be provided in the housing 51. The one or moreguide bars 53 and 54 extend in parallel with the screw 52 or 52 a in astate in which the guide bars are spaced apart from the screw 52 or 52a.

A plurality of guide bars 53 and 54 are provided in the housing 51 suchthat the screw holder 56 or 56 a is not inclined to either left or rightwith respect to the screw 52 or 52 a, and the screw 52 can be positionedbetween the plurality of guide bars 53 and 54.

The motor case 61 and the pair of housings 51 can be integrally formed.In some implementations, a single cover member 66 can cover the motorcase 61 and the pair of housings 51.

For example, the cover member 66 is fastened to the motor case 61 tocover the driving force transmission part and is fastened to the pair ofhousings 51 to cover the screws 52 and 52 a, the guide bars 53 and 54,and the screw holders 56 and 56 a.

It should be noted that the cover member 66 can be composed of aplurality of portions respectively shielding the driving forcetransmission part and the screw units 50 and 50 a to open and close eachof relevant parts independently.

In some implementations, since the drive device 40 is provided in theform of a single module, the drive device 40 is compact, making itpossible to easily mount the drive device 40 in the door part 31.

In some implementations, since the single cover member 66 covers themotor case 61 and the pair of housings 51 together, there is anadvantage in that access to the driving force transmission part or thehousing 51 is easily made when the cover member 66 is separated.

In some implementations, a lift detection device 55 can be provided inthe screw unit 50 a on one side among the screw units 50 and 50 a on theleft and right sides. The lift detection device 55 is configured todetermine whether the lifting device 80 has been lifted or lowered, andfurther determine whether the lifting device 80 has been lifted orlowered based on the operation of the drive device 40.

The lift detection device 55 can be mounted on the cover member 66 andcan be disposed vertically along the screw unit 50 a.

The lift detection device 55 can include a pair of detection sensors 552and 553. As the detection sensors 552 and 553, a sensor that detects themagnet 563 can be used. The detection sensors 552 and 553 can betypically a Hall sensor that detects the position of a magnet. It isnoted that another sensor or device for detecting the magnet 563 can beprovided in place of the Hall sensor.

FIG. 12 is a diagram illustrating a perspective view of a liftingdevice. FIG. 13 is a diagram illustrating a view showing a state inwhich an upper frame of the lifting device is lifted. FIG. 14 is adiagram illustrating a partial enlarged view showing a state in which alifting device is coupled to a lever.

Referring to FIGS. 12-14 and FIG. 22, the lifting device 80 can beprovided on the bottom of the inner surface of the drawer part 32 andcan be detachably provided inside the drawer part 32. The lifting device80 can be formed to have a size corresponding to the front space S1 ofthe drawer part 32. For example, the bottom surface of the front spaceS1 can have a corresponding size to the top surface of the liftingdevice 80.

In some implementations, the lifting device 80 can include an upperframe 82, a lower frame 83, and a scissor assembly 84 disposed betweenthe upper frame 82 and the lower frame 83.

For example, the upper frame 82 is formed in a rectangular frame shapecorresponding to the size of the front space S1 inside the drawer part32, and the support plate 81 can be mounted on the upper surface of theupper frame 82.

The upper frame 82 is moved in the vertical direction of the liftingdevice 80 and supports food or the basket 36 together with the supportplate 81.

The upper frame 82 can include a frame portion 821 having a peripheralshape of the upper frame 82 as a whole, and a partition portion 822 thatdivides a space inside the frame portion 821 into left and right sides.

The frame portion 821 and the partition portion 822 are configured todefine an outer frame and support the support plate 81. In someimplementations, the frame portion 821 and the partition portion 822 canbe formed of a metal material, and can be formed in a shape in whichboth ends are bent to increase strength and prevent deformation.

Further, a slide guide 824 which accommodates the end of the scissorassembly 84 to guide the movement of the scissor assembly 84 can beformed in the lower surface of the frame portion 821.

The scissor assemblies 84 can be arranged in spaces 823 and 823 a onboth sides of the partition portion 822, respectively.

The slide guide 824 can define a long hole 824 a through which thescissor assembly 84 passes. Accordingly, the scissor assembly 84 can bemoved along the slide guide 824.

The lower frame 83 can have the same or similar structure as the upperframe 82 only in a direction different from that of the upper frame 82.

The lower frame 83 can include a frame portion and a partition portion.Further, a slide guide 834 which accommodates the end of the scissorassembly 84 to guide the movement of the scissor assembly 84 can beformed in the upper surface of the lower frame 83.

The slide guide 834 can define a long hole 834 a through which thescissor assembly 84 passes. Accordingly, the scissor assembly 84 can bemoved along the slide guide 834.

The scissor assemblies 84 can be provided on both left and right sides,respectively, and the scissor assemblies 84 on both sides operate byreceiving the driving force from the drive motor 64, such that thescissor assemblies 84 can be lifted and lowered by the same height atthe same time.

Therefore, even when supporting a heavy load, the heavy load can beeffectively lifted and lowered by the pair of the scissors assemblies 84in which a force is independently applied to both the scissorassemblies. For example, the scissors assembly 84 can enable the upperframe 82, that is, the support plate 81 to be lifted in a horizontalstate.

The scissor assembly 84 can include a first scissor frame 841 in theshape of a rectangular frame, and a second scissor frame 845 in theshape of a rectangular frame, which is rotatably connected to the firstscissor frame 841.

A left-right width of the second scissor frame 845 can be shorter than aleft-right width of the first scissor frame 841. Accordingly, the secondscissor frame 845 can be connected to the first scissor frame 841 whilebeing positioned within an area defined by the first scissor frame 841.

The first scissor frame 841 can include a lower shaft 841 a and an uppershaft 841 b extending in a horizontal direction. In someimplementations, the lower shaft 841 a is rotatably supported by thelower frame 83, and the upper shaft 841 b is disposed to pass through asliding guide 824 of the upper frame 82.

The first scissor frame 841 can be connected to a first rod and an uppershaft extending in a vertical direction.

The second scissor frame 845 can include a lower shaft and an uppershaft extending in a horizontal direction, and a first rod and a secondrod extending in a vertical direction.

The first scissor frame 841 can include a scissor-side connectionportion 842 protruding to be connected to the lever 42. The scissor-sideconnection portion 842 can include an extension portion 842 b extendingfrom the first scissor frame 841 and a connection portion 842 c formedat an end of the extension portion 842 b.

The lever 42 can include a lever-side connection portion 422accommodating the scissor-side connection portion 842 for coupling withthe scissor-side connection portion 842. The scissor-side connectionportion 842 can be formed in a shape corresponding to an accommodatingspace 422 c of the lever-side connection portion 422. For example, thescissor-side connection portion 842 can be formed in a shape extendingfrom a circular rotation shaft to one side, and can be formed in a shapecorresponding to a rotation boss portion 422 b and a lever-sideprotrusion 422 a.

For example, the end of the scissor-side connection portion 842 can beformed in a non-circular shape. Therefore, when the lever 42 is rotatedwhile the scissor-side connection portion 842 is accommodated in thelever-side connection portion 422, the lever 42 is prevented fromspinning with the scissors-side connection portion 842. In someimplementations, the scissor-side connection portion 842 can transmit agreater force for operation of the lifting device 80.

FIG. 15 is a block diagram schematically showing a controller andcomponents connected to the controller. FIG. 16 is a flow chart showingthe drawing-in/out and lifting/lowering operation of the drawer door.FIGS. 17 to 22 are views showing the state of the drawer door when thedrawer door is drawn in/out and lifted/lowered.

Referring to the drawings, in the refrigerator 1, both the rotating door20 and the drawer door 30 can be maintained in a closed state as shownin FIG. 17 when food has been stored. In this state, the user can storefood by drawing out or in the drawer door 30.

A plurality of drawer doors 30 can be provided on upper and lower sides.The drawer door 30 provided at a lower side among the drawer doors 30can be disposed adjacent to the upper drawer door 30 without a separatehandle for drawing in and out. For example, a gap is hardly seen betweenthe upper drawer door 30 and the lower drawer door 30, so that the frontappearance of the refrigerator 1 can look very neat and luxurious.

In order to draw in/out the lower drawer door 30, the user can input anoperation for drawing in/out the drawer door by operating a manipulationpart 212, 301, or 302. In this case, the user's operation can beperformed by touching the manipulation part 212 or 301 provided in thefront surface of the rotating door 20 or the door 30 and an operationfor opening the door 30 can be input through the manipulation part 302provided at the lower end of the door 30.

In some implementations, the manipulation part 301 and the manipulationdevice 302 can be configured to individually operate the drawing-in/outof the door 30 and the lifting and lowering of the lifting device 80. Insome implementations, the user can hold the handle of the door 30 andopen the door 30.

Hereinafter, opening and lifting of the lower drawer door 30 b among thedoors 30 disposed in the upper and lower sides is described as anexample, but both the doors 30 disposed in the upper and lower sides aredrawn in/out and lifted/lowered in the same manner. [S100: step foroperation input]

When the controller 90 for controlling the overall operation of therefrigerator 1 determines that an operation input is valid in anoperation input step, the controller 90 can control a draw-out motor 14such that the operation of the draw-out motor 14 is started.

When the draw-out motor 14 is driven by an instruction of the controller90, the drawer door 30 is drawn out forward. The drawer door 30 can bedrawn out while the draw-out rail 33 is extended.

A draw-out rack 34 provided on the bottom of the drawer door 30 can becoupled with a pinion gear 141 that is rotated when the draw-out motor14 provided in the cabinet 10 is driven, and thus the drawer door 30 isdrawn in and out according to the driving of the draw-out motor 14.

The drawer door 30 can be drawn out until the drawer door 30 is in astate as shown in FIGS. 18 and 19. For example, a draw-out distance ofthe drawer door 30 can be at least a distance in which the front spaceS1 inside the drawer part 32 can be completely exposed to the outside.Therefore, as shown in FIGS. 18 and 19, when the drawer door 30 has beendrawn out, a container or food does not interfere with the doors 20 and30 or the cabinet 10 disposed above the lifting device 80 when thelifting device 80 is lifted or lowered.

A state in which the drawer door 30 is drawn out is described in detail.When the drawer door 30 is drawn out for lifting, it is typicallyrequired that the front space S1 has been completely drawn out of thelower storage space 12.

For example, the rear end L1 of the front space S1 is required to befurther drawn out than the front end L2 of the cabinet 10 or the upperdoor 20, and to be positioned more forward than the front end L2 inorder to prevent interference when the lifting device 80 is lifted.

In some implementations, as shown in FIG. 19, the drawer door 30 can bedrawn out only to a position to avoid interference when the liftingdevice 80 is lifted rather than the entire drawer part 32 is notcompletely drawn out. For example, at least a part of the rear space S2of the drawer part 32 is located inside the lower storage space 12. Thatis, the rear end L3 of the drawer part 32 is located at least inside thelower storage space 12.

Therefore, even when the drawer door 30 including the drive device 40and the lifting device 80 has a weight in which the weight of a storageobject is added to the weight of the drawer door 30 itself, it ispossible to ensure a stable drawing in/out and lifting operation withoutsagging or damage of the draw-out rail 33 or the drawer door 30 itself.

For example, the draw-out distance of the lower drawer door 30 b can bedetermined by the draw-in/out detection device 15 disposed in thecabinet 10 and/or the lower drawer door 30 b.

The draw in/out detection device 15 can be configured with a detectionsensor that detects the magnet 389 to detect a state in which the lowerdrawer door 30 b has been completely drawn out or closed.

For example, as shown, the magnet 389 can be provided on the bottom ofthe drawer part 32 and a detection sensor can be provided in the cabinet10. The drawing-in/out detection device 15 can be provided at a positioncorresponding to a position of the magnet 389 when the lower drawer door30 b has been closed and a position of the magnet 389 when the lowerdrawer door 30 b has been completely drawn out. Accordingly, it ispossible to determine the state of the drawing in/out of the lowerdrawer door 30 b by the drawing-in/out detection device 15.

Further, a switch can be provided at a position where the lower drawerdoor 30 b has been completely drawn in and a position at which the lowerdrawer door 30 b has been completely drawn out to detect thedrawing-in/out of the lower drawer door 30 b and count the number of thedraw-out motor 14, or the drawing-in/out of the lower drawer door 30 bcan be detected by a sensor that measures the distance between the rearsurface of the door part 31 and the front end of the cabinet 10.

When the draw-out detection device 152 detects that the drawer door 30has been drawn out to a set distance, the controller 90 can determinethat the drawer door 30 has been completely drawn out, and stop thedriving of the draw-out motor 14 in order to complete the drawing-in/outof the drawer door 30. [S200: step of drawing out a drawer door]

For example, in a state in which the drawer door 30 has been completelydrawn out, the draw-out motor 14 can be in a brake state such that thedraw-out motor 14 is no longer rotated. That is, the drawer door 30needs to be kept in a draw-out state while the lifting device 80 insidethe drawer door 30 is operating. To this end, the draw-out motor 14 canbe a motor (generally referred to as a braking motor or a brake motor)provided with a brake capable of selectively restraining a motor.

For example, when the drawer door 30 is moved or closed while thelifting device 80 is being driven, there is a possibility of a safetyaccident. Further, when the drawer door 30 is moved or closed during theoperation of the lifting device 80, a problem of falling or damage ofthe food being stored may occur, and a problem of damage to thestructure for lifting or the refrigerator itself may occur. Therefore,the drawer door 30 should be able to maintain a fixed state in which thedrawer door 30 is not drawn-in/out even though an external force isapplied to the drawer door 30 at least during the operation of thelifting device 80.

The draw-out motor 14 can be prevented from rotating by its own brakingstructure even when an external force is applied. The drawer door 30 canbe restrained such that the drawer door 30 is maintained in a drawn-outstate. [S300: step of restraining door draw-in/out]

In some implementations, the drive device 40 and the lifting device 80are not operated until the drawer door 30 is completely drawn out asshown in FIGS. 18 and 19, and the lifting device 80 is in a lowest statewhich refers to the lifting device being located in a lowest position.

Before the lifting device 80 is lifted, the lever 42 and the screwholder 56 are located at the lowest position as shown in FIG. 20, andthe lift detection device 55 can detect this and determine that thecurrent state is a state in which the lifting device 80 has beencompletely lowered.

For example, when the lifting device 80 has been completely lowered, thescrew holder 56 can be positioned at the lowest position. By way offurther example, the magnet 563 provided in the screw holder 56 ispositioned at a position corresponding to the detection sensor locatedon the lower side among the pair of detection sensors 552 and 553.Accordingly, since the magnet 563 is detected by the detection sensorlocated below, it can be determined that the lifting device has beencompletely lowered.

When it is determined that the lifting device 80 has been completelylowered by the lift detection device 55, the drive device 40 can startoperation upon the user's operation or when the drawer door 30 has beencompletely drawn out.

When the lift detection device 55 determines that the lifting device 80has not been completely lowered, the lift detection device 55 can outputan abnormal signal to cause the drive device 40 not to be operated.

When the drawer door 30 has been drawn out by a set distance, thecontroller 90 can instruct the lifting motor 64 to operate. Further, thedrive device 40 is operated by the lifting motor, and the lifting device80 is lifted as shown in FIG. 21.

When the drawer door 30 is completely drawn out and the draw-out motor14 is stopped, the lift motor 64 can be driven by the controller 90. Thelifting device 80 can be configured to be operated only in a situationin which the drawer door 30 has been sufficiently drawn out to ensurethe safe lifting of the food or basket 36 seated on the lifting device80.

For example, when the drawer door 30 is drawn out and the front space S1is completely exposed to the outside, the lifting device 80 is operated,so that the basket 36 seated on the lifting device 80 or stored food areprevented from interfering with the other doors 20 and 30 or the cabinet10.

In some implementations, in order to prevent the user's safety anddamage to stored food, the lifting device 80 can be configured to startoperation after a set time has elapsed after the draw-out of the drawerdoor 30 is confirmed.

For example, the lifting of the lifting device 80 can refer that theupper frame 82 is lifted by the scissor assembly 84, and the lowering ofthe lifting device 80 can refer that the upper frame 82 is lowered bythe scissor assembly 84.

The drive device 40 is connected to the lifting device 80, and thus, thedriving force can be transmitted to the lifting device 80. With thestart of the operation of the drive device 40, the driving force istransmitted to the lifting device 80, and the lifting of the liftingdevice 80 is started.

For example, when the lifting motor 64 rotates forward and reversely bya lifting or lowering signal of the lifting device 80, the drive device40 starts an operation. A plurality of gears between the lifting motor64 and the screws 52 and 50 a are rotated by driving of the liftingmotor 64, and thus the screws 52 and 50 a are rotated. As the screws 52and 50 a on both sides are rotated, the screw holder 56 is lifted andthe lever 42 is rotated.

When the lever 42 is moved upward, the height of the first rod 842 a ofthe first scissor frame 841 connected to the lever 42 increases due toincrease in the height of the lever 42. In some implementations, thescissor assembly 84 can be unfolded by increasing the height of thefirst rod 842 a of the first scissor frame 841.

Eventually, as the scissor assembly 84 is unfolded, the upper frame 82is lifted, and the basket 36 or food seated on the support plate 81 islifted. Finally, as shown in FIG. 21, the lifting device 80 is lifted tothe maximum height.

In some implementations, the lifting device 80 is stopped when liftingdevice 80 is lifted to a sufficient height to facilitate access to thefood or basket 36 seated on the lifting device 80 as shown in FIG. 21.In the above state, the user can easily lift the food or basket 36without excessively bending the waist. [S400: step of lifting thelifting device]

When the lifting device 80 has been completed lifted, the lever 42 andthe screw holder are located at the highest position as shown in FIG.20, and the lift detection device 55 can detect this and determine thatthe current state is a state in which the lifting device 80 has beencompletely lifted.

When it is determined by the lift detection device 55 that the liftingdevice 80 has been completely lifted as shown in FIG. 21, the liftingmotor 64 is stopped. In this state, the lifting device 80 is locatedinside the drawer part 32, but the food or basket 36 seated on thelifting device 80 is located at a higher position than that of the openupper surface of the drawer part 32, thus enabling easy access by theuser.

For example, since it is not necessary to bend the waist excessively tolift the basket 36, a safer and more convenient operation is possible.

The state in which the lifting device 80 is lifted to the maximum heightis described more detail with reference to FIG. 21. The lifting device80 is positioned at least at a lower position than that of the upper endof the drawer part 32.

When viewed from the basket 36 in a state where the basket 36 is seatedon the drive device 40, the upper end H1 of the basket 36 can be liftedto a higher position than the upper end H2 of the lower storage space12. The height can be the most suitable height for use since the usercan reach out and lift the basket 36 without bending the waist.

For example, the drive device 40 has a structure that is lifted andlowered inside the drawer part 32, but when the container 36 has beenseated in the lifting device 80, the basket 36 can be positioned at aheight at which a user easily accesses the basket 36. [S500: step ofstopping the lifting device]

When the lifting device 80 reaches a set height, the lifting motor 64 isstopped and a timer 91 counts a stop time of the lifting motor 64. Forexample, in a state in which the lifting device 80 has been lifted, thelifting device 80 waits for a set period of time.

In some implementations, the controller 90 can determine whether thetime counted by the timer 91 reaches the set period of time. When thecontroller 90 determines that the set period of time has elapsed afterthe lifting device 80 is stopped, the lifting motor 64 starts to rotatereversely and the lifting device 80 is lowered.

For example, the set period of time can be set to approximately 90seconds. The set period of time can be set to a period of timesufficient for the user to store food. When the set period of time istoo short, the lifting device 80 can be lowered before completingstorage of the food, causing inconvenience in use. When the set periodof time is too long, the drawer door 30 is exposed for a long time in anopen state and the loss of cold air can become excessive, thusdeteriorating cooling performance and causing an increase in powerconsumption. Accordingly, the set period of time can be set to about 90seconds.

The set period of time can be set by the user through operation throughthe manipulation part 212 or by a speech input through a microphone, andcan be adjusted to an appropriate time desired by the user.

In some implementations, the elapse of the set period of time can bedisplayed on the screen through the display 211 or externally outputthrough the speaker 92 while the lifting device 80 is stopped andwaiting. Accordingly, the user can recognize a change in the set periodof time and perform a food storage operation, and can determine when thedrawer door 30 is closed. [S610: step of determining the elapse of theset period of time]

In some implementations, when the user wants to close the drawer door 30because completing the food storage operation before the set period oftime has not elapsed, an operation of lowering the lifting device 80 canbe input through operation through any one of the manipulation parts212, 301 or 302.

In some implementations, the user can identify the remaining period oftime before the drawer door 30 is closed through the screen output bythe display 211 or the speech output by the speaker 92, and accordingly,determine the food storage operation speed. Further, even when too muchremaining period of time remains until the drawer door 30 is closed, thelifting device 80 can be lowered and the drawer door 30 can be drawn-inby operating any one of the manipulation parts 212, 301, or 302.

For example, when the lifting device 80 is lifted, the user can input anoperation by operating any one of the manipulation parts 212, 301, or302 to lower the lifting device 80 and draw in the drawer door 30 beforethe set period of time has elapsed. [S620: step for input a loweringoperation]

When the set period of time has elapsed or the lowering operation isinput, the controller 90 can instruct the lifting motor 64 to operate,and the lifting device 80 can start to be lowered as shown in FIG. 25.

The lowering of the lifting device 80 can be performed by reverserotation of the lifting motor 64, and can be gradually performed througha process opposite to the process of lifting the lifting device 80described above.

In some implementations, when the lifting device 80 has been lowered asshown in FIG. 19, the lift detection device 55 can detect the completionof the lowering of the lifting device 80. For example, when the magnet563 is detected by the detection sensor located below, the controller 90determines that the lifting device 80 has been completely lowered andstops driving of the lifting motor 64. [S700: step of lowering thelifting device]

When a lowering completion signal of the lifting device 80 is received,the controller 90 simultaneously can release the restraint of thedraw-out motor 14. The controller 90 can release the braking of thedraw-out motor 14 or release the restraint of the drawer door 30 so thatthe drawer door 30 is in a condition capable of being drawn in. Forexample, the controller 90 can completely restrain the drawing in/out ofthe drawer door 30 until the lifting device 80 has been lowered so thatthe lifting operation of the lifting device 80 is stably made and at thesame time, food is stored and food storage operation is also easily andsafely performed. [S800: step of releasing restraint of drawing-in/outof the door]

In some implementations, when the braking of the draw-out motor 14 isreleased, the controller 90 can instruct the draw-out motor 14 to rotatereversely. The drawer door 30 can be drawn in by the reverse rotation ofthe draw-out motor 14. [S900: step of drawing in the drawer door]

The draw-out motor 14 can rotate reversely until the drawer door 30 hasbeen completely closed. When the drawer door 30 has been completelyclosed, a draw-in detection device 151 can detect the completion of thedrawing-in of the drawer door 30. In some implementations, when thedrawer door 30 has been completely drawn in, the standby state ismaintained such that the drawer door 30 is opened again.

Further, the controller 90 continuously maintains the standby stateuntil a user's operation is input, and controls devices constituting afreezing cycle so as to perform an operation for cooling the interior ofthe refrigerator.

In some implementations, when the door 30 is kept closed for a longperiod of time, the door 30 cannot be opened even when the draw-outmotor 14 is driven to open the door 30. Hereinafter, a state in whichthe door 30 cannot be opened and an operation for solving it will bedescribed in more detail with reference to the drawings.

FIG. 23 is a cross-sectional view showing a state in which the drawerdoor cannot be opened. FIG. 24 is a graph showing a change in pressureduring operation for opening the drawer door.

The refrigerator is kept in a closed state as shown in FIG. 3. Forexample, in order to maintain the airtightness of the refrigerator 1,the door gasket 317 is in close contact with the front surface of thecabinet 10 and the front surface of the barrier 121. In someimplementations, the door gasket 317 can be kept in a compressed state,so that the rear surface of the door part 31 and the front surface ofthe cabinet 10 and the barrier 121 are spaced apart by a compressiondistance L1.

In some implementations, when the door 30 is drawn out, the door gasket317 can extend in a state in which the door gasket 317 is in closecontact with the front surface of the cabinet 10 and the front surfaceof the barrier 121 as shown in FIG. 23. For example, the door gasket 317is in contact with the front surface of the cabinet 10 and the frontsurface of the barrier 121 so that the door part 31 and the cabinet 10can be spaced apart from each other by an extension distance L2 due tothe elasticity of the door gasket 317 itself and the structure of thegasket connection portions 317 b and 317 c while the storage space isbeing kept airtight.

When the distance between the door part 31 and the cabinet 10 becomeslarger than the extension distance L2, the door gasket 317 can beseparated from the front surface of the cabinet 10 and the front surfaceof the barrier 121 and the storage space 12 can be further opened whilethe door 30 is being drawn out.

However, while the distance between the door part 31 and the cabinet 10increases to the extension distance L2, the inside of the storage space12 is in a negative pressure state. For example, when the storage space12 has been closed, the volume of the storage space 12 increases due tothe movement of the door 30, and thus the storage space 12 becomes anegative pressure state.

When the storage space 12 is in a negative pressure state, a greaterforce is required to draw out and open the door 30, and in some cases,the door 30 can be in an unopenable state in which the door 30 cannot beopened.

It is noted that a higher output of the draw-out motor 14 is expected toovercome the negative pressure of the storage space 12 and to draw outthe door 30.

FIG. 24 shows a change in pressure required to open the door 30 overtime while the door 30 is closed.

The draw-out motor 14 can have an output to draw in/out the door 30 in ageneral situation. However, when the door 30 is closed for a long periodof time, a situation in which the door 30 cannot be opened may occurdepending on the internal state of the storage space 12.

For example, when a drain tube in communication with the machine room 3is blocked due to the negative pressure when an attempt to open the door30 is made, and the frost generated when the storage space 12 is used asa freezer, or a greater force is required to open the door 30 due tofreezing of the door gasket 317 or excessive application of grease, thedoor 30 may not be opened normally.

Referring to FIG. 24, when the door 30 is initially opened in a state inwhich the door 30 is closed for a certain period of time, a forcerequired to open the door 30 can correspond to −133 Pa to −170 Pa and anegative pressure of 153 Pa on average can be generated. For example,when the area of the door 30 is 0.238 m², an average force of 3.7 kgfmay be required to open the door 30 on which an average negativepressure of 153 Pa works, and an average force of 4.1 kgf may berequired to open the door 30 on which a maximum negative pressure of 170Pa works.

Therefore, even when the door 30 is in an unopenable state after theinitial opening of the door 30, the door 30 can be opened with lessforce when it is attempted to open the door 30 continuously. A forcerequired in the case of repetitive opening of the door 30 can correspondto −62 Pa to −103 Pa, and an average negative pressure of 87 Pa isgenerated. Accordingly, when it is continuously attempted to open thedoor 30 after stopping the motor when the door 30 cannot be opened, thedoor 30 can be opened with a smaller force.

Therefore, a problem in which it is impossible to open the door 30 canbe solved by continuously operating the draw-out motor 14 without theneed to excessively increase the output of the draw-out motor 14 basedon the maximum negative pressure.

The process of drawing out the door 30 to which the operation ofcontinuously opening the door 30 is applied will be described in moredetail with reference to the drawings.

FIG. 25 is a flowchart sequentially illustrating an operation of drawingout the drawer door.

As shown in FIG. 25, in order to store food in the door 30 while thedoor 30 is closed, the manipulation part 212, 301, or 302 can beoperated to input the operation of opening the door 30.

The operation for drawing out the door 30 is started by the user'soperation input through the manipulation part 212, 301, or 302. Theoperation after the drawing-out of the door 30 can be performed as shownin S100 of FIG. 16.

The draw-out motor 14 starts to be driven by the user's operationthrough the manipulation part 212, 301, or 302, and the door 30 is drawnout forward by engagement of the pinion gear 141 and the draw-out rack34 according to the driving of the draw-out motor 14. [S210]

The timer can count the elapsed time at the same time as the driving ofthe draw-out motor 14 is started. Then, the controller 90 can determinewhether the counted elapsed time has passed the set period of time. Forexample, it is determined whether or not a set period of time haselapsed after the start of the driving of the draw-out motor 14.

The set period of time is for detecting a state in which it is hard toopen the door 30 at the beginning of the draw-out of the door 30, andcan be set to a period of time during which the door gasket 317 isseparated and the draw-out is performed after the door 30 is opened. Forexample, the set period of time can be set to one second. That is, thecontroller 90 can determine whether the door 30 is normally opened or inan unopenable state after one second. [S220]

When the elapsed time passes the set period of time, it is determined bycomparing the draw-out distance of the door 30 with a set distance. Forexample, the set distance can correspond to the extension distance L2.Therefore, when the draw-out distance is longer than the set distance(extension distance L2), it can be determined that the door gasket 317is separated from the cabinet 10 and the barrier 121 and an operation ofopening the door 30 normally is performed.

Further, when the draw-out distance is shorter than the set distance(extension distance L2), it can be determined that the door gasket 317is still in close contact with the cabinet 10 and the barrier 121 andthe door 30 cannot be opened. For example, the draw-out distance can bedetected by driving of the draw-out motor 14. A detection value by afrequency generator (FG) of the draw-out motor 14 can be set to 30 (FG30) or less, and the draw-out distance of the door 30 can beapproximately 20 to 30 mm.

That is, when the door 30 is not drawn out by the extension distance L2until one second has elapsed after the draw-out motor 14 is driven, itis determined that the storage space 12 is still in a closed state bythe door gasket 317, and the door is in an unopenable state due to thenegative pressure of the storage space 12. [S230]

When it is determined that the draw-out distance is shorter than the setdistance, the controller 90 can perform a continuous door openingoperation to open the door 30. The continuous door opening operation canrefer that the draw-out motor 14 is re-driven in the direction in whichthe door 30 is drawn out after the draw-out motor 14 is stopped. In someimplementations, the continuous door opening operation can refer thatthe draw-out motor 14 is rotated reversely in the direction in which thedoor is closed and then rotated forward in the direction in which thedoor is drawn out.

In some implementations, the continuous door opening operation can beperformed at the moment when the operation for opening the door 30 isstarted, but it is determined that the door 30 cannot be opened, and canbe repeatedly performed at least once or multiple times continuously. Insome implementations, the continuous door opening operation can berepeatedly performed even at regular time intervals. [S240]

Through the continuous door opening operation, the door 30 can beeventually opened, and the door part 31 and the front surface of thecabinet 10 are spaced apart from each other by the distance L2 or more.Accordingly, the door gasket 317 is separated from the cabinet 10 andthe barrier 121 and the storage space 12 can be opened. In someimplementations, when the storage space 12 is opened, the negativepressure in the storage space 12 is relieved, so that the door 30 can becontinuously drawn out by the draw-out motor 14.

Further, when the draw-out distance of the door 30 is greater than theset distance at the time when the set period of time has elapsed, thedoor 30 can be normally opened, and the door 30 can also be drawn outnormally. [S250]

In some implementations, while the door 30 is normally opened and thedoor 30 is being drawn out, the controller 90 can determine whether anobstacle is detected. For example, a situation in which a normaloperation is impossible due to the obstacle can occur during thedraw-out of the door 30.

When the door 30 cannot be completely opened normally while the draw-outmotor 14 is being driven for the draw-out of the door 30, the controller90 can determine that the obstacle is recognized. For example, when anobject or a person's body is located on a path through which the door 30is drawn in/out, food is caught in the door 30, structural damage of thedoor 30 occurs, or the like, it can be determined that an obstacleexists or a failure condition occurs when the door 30 is drawn out.

When the door 30 is not completely drawn out within a set period oftime, or when a load greater than a set load is applied to the draw-outmotor 14, the controller 90 can determine that it is hard to open thedrawer door 30 normally due to an obstacle.

In some implementations, when the controller 90 determines that thefailure condition occurs, the controller 90 can immediately output thefailure condition (e.g., via a door opening failure signal) through thedisplay 211 or the speaker 92. Therefore, it is possible to induceimmediate action by the user. [S260]

When the controller 90 determines that an obstacle exists, thecontroller 90 stops the operation of the draw-out motor 14. When thedraw-out motor 14 is continuously operated, damage to food, a safetyproblem of the user may occur, or damage to the refrigerator itself maybe caused, so that the controller 90 can stop the draw-out motor 14.When the draw-out of the draw-out door is stopped, the user may removethe obstacle or the failure condition.

In some implementations, the controller 90 can allow the door 30 to bedrawn in while the retractable motor 14 rotates reversely after thedraw-out motor 14 is stopped. Since cooling performance can bedeteriorated and food can be damaged when the door 30 is left in a statein which the door is drawn out for a long period of time, the door 30can be drawn in and then closed. Of course, as soon as the controller 90determines that an obstacle exists, the controller 90 can allow thedraw-out motor 14 to rotate reversely to close the door 30. [S270]

When the door 30 has been drawn in, the draw-out motor 14 is stopped andthe door 30 remains closed until the user's operation is input again. Insome implementations, when the existence of an obstacle is not detecteduntil the door 30 is completely drawn out, the draw-out motor 14 isstopped and the door 30 has been completely drawn out. [S280]

Thereafter, the user can store food in the door 30 in the draw-outstate, and the lifting device 80 is driven so that the food can bestored more easily. Then, after the storage operation is finished, thedoor 30 can be drawn in again.

In some implementations, the drawer door is configured to beautomatically drawn in and out by driving a draw-out motor, therebyimproving user convenience.

In particular, when the drawer door is closed for a long period of timedue to a long period of non-use, when the storage space is used as afreezing space and the temperature is low, when the storage space iscompletely sealed, or when the drawer door is kept in close contact withthe cabinet by the magnetic force of the gasket, the opening of the doormay fail since the inside of the storage space momentarily becomes anegative pressure upon initial drawing out of the drawer door or thedraw-out rail is pressed and then a greater force is required to openthe drawer door.

However, according to implementations of the present disclosure, evenafter the set period of time has elapsed after the initial driving ofthe draw-out motor, when the drawer door is not drawn out more than aset distance in which the drawer door can be substantially opened, anoperation for opening the door is additionally performed to open thedoor.

Accordingly, there is an advantage in that the drawer door can beprevented from being unopened to improve the convenience of use, and theoperation of drawing in and out the drawer door can be more smoothlyperformed.

Further, even when the output of the draw-out motor for opening thedrawer door is not designed to be excessively high, it is possible toensure a reliable draw-out operation of the door through the repetitiveopening operation of the draw-out motor.

Therefore, there is an advantage in that manufacturing cost can bereduced by appropriate design of the draw-out motor, and the volume ofthe draw-out motor is not excessively large, thereby preventing loss ofthe storage space.

What is claimed is:
 1. A refrigerator comprising: a cabinet defining afirst storage space; a door including (i) a drawer part that defines asecond storage space inside the first storage space and (ii) a door partthat is mounted on a front surface of the drawer part to open and closethe second storage space; a door gasket made of an elasticallydeformable material and provided along a periphery of the door part toseal, based on the door being closed, a gap between the cabinet and thedoor; a draw-out motor configured to provide a driving force for adrawing out operation of the door; a detector configured to detect anopen/close state of the door; a manipulation part configured to receiveuser input to control an operation of the draw-out motor; and acontroller configured to control the draw-out motor, wherein thecontroller is configured to: count a number of rotations of the draw-outmotor for a set period of time based on the draw-out motor being startedfor opening of the door according to the received input of themanipulation part, and stop and re-operate, based on a draw-out distanceof the door being shorter than a set distance, the draw-out motor. 2.The refrigerator of claim 1, wherein the controller is configured tore-operate the draw-out motor in a direction in which the door is drawnout after the draw-out motor is stopped.
 3. The refrigerator of claim 1,wherein the controller is configured to re-operate the draw-out motor to(i) rotate in a reverse direction in which the door is drawn in and (ii)rotate, based on the draw-out motor being stopped, in a forwarddirection in which the door is drawn out.
 4. The refrigerator of claim1, wherein the controller is configured to re-operate the draw-out motorrepeatedly a plurality of times.
 5. The refrigerator of claim 1, whereinthe draw-out distance is calculated based on a frequency generator (FG)detection signal of the draw-out motor.
 6. The refrigerator of claim 5,wherein the detector is configured to detect a completion of the drawingout operation of the door.
 7. The refrigerator of claim 1, wherein theset distance is set to a distance extendable while the door gasket is incontact with the cabinet.
 8. The refrigerator of claim 1, wherein thedoor gasket includes: a gasket fixing portion fixed to a rear surface ofthe door part; a close-contact portion contacting a front surface of thecabinet and including a magnet; and a connection portion that isconfigured to connect the gasket fixing portion to the close-contactportion and that extends based on the open/close state of the door,wherein the front surface of the cabinet is made of a steel material orincludes a magnetic material.
 9. The refrigerator of claim 8, whereinthe set distance is set to a maximum distance through which the doorgasket is able to extend while the close-contact portion is attached tothe cabinet.
 10. The refrigerator of claim 6, wherein the set distanceis within a range of 20 mm to 30 mm.
 11. The refrigerator of claim 1,wherein the set period of time is a period of time until the door gasketis completely separated from the cabinet in a state in which the doorthat was opened is closed.
 12. The refrigerator of claim 1, wherein thecontroller is configured to output, based on the door not being openedafter the draw-out motor is re-operated, a door opening failure signal.13. The refrigerator of claim 1, further comprising a display or aspeaker, wherein the controller is configured to output, based on thedoor not being opened within the set period of time, a door openingfailure through the display or the speaker.
 14. The refrigerator ofclaim 13, wherein the controller is configured to reversely rotate,based on the door not being opened within the set period of time, thedraw-out motor to close the door.
 15. The refrigerator of claim 1,wherein the draw-out motor is provided on a bottom of the cabinet, andwherein the drawer part includes a draw-out rack that is coupled to apinion rotated by the draw-out motor on a bottom thereof.
 16. Therefrigerator of claim 1, wherein an output of the draw-out motor issmaller than a value for overcoming a maximum negative pressure based onthe door being opened.
 17. The refrigerator of claim 1, wherein thesecond storage space that is opened and closed by the door is a freezingspace.
 18. The refrigerator of claim 1, further comprising: a drivedevice provided inside the door part; and a lifting device providedinside the drawer part and configured to be connected to the drivedevice based on the door part and the drawer part being coupled to liftthe drawer part.
 19. The refrigerator of claim 18, further comprising: alift detection device configured to detect a completion of a lifting andlowering operation of the lifting device, wherein the draw-out motor isconfigured to be driven based on the lifting device being lowered. 20.The refrigerator of claim 18, wherein the door is drawn out to adistance where a front space inside the drawer part in which the liftingdevice is disposed is completely exposed, and a rear end of the drawerpart is positioned inside the first storage space.